Shift Work and Sleep: Sorting the Evidence From the Noise
Night work asks you to be alert at the trough of your circadian cycle and to sleep at its peak, which no amount of discipline changes.
Key takeaways
- Useful pre-shift nap: 20-30 minutes
- Anchor sleep block: around 4 hours at a fixed clock time
- Most useful single change: Wear dark glasses travelling home after a night shift.
- Commonest mistake: Driving while fighting to stay awake.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
What it is
Working hours that conflict with the body clock, and the sleep problems that follow. It sits within Sleep. What follows are the published numbers, not the ones that get passed around.
The numbers, in one place
| Measure | Figure |
|---|---|
| Useful pre-shift nap | 20-30 minutes |
| Anchor sleep block | around 4 hours at a fixed clock time |
| Light to stay alert | bright light in the first half of a night shift |
| Light to avoid | morning daylight on the commute home |
| Caffeine cut-off within a shift | the final 4-6 hours |
What helps
Here is what the evidence supports doing. Some of it will already be familiar.
- Wear dark glasses travelling home after a night shift
- Make the bedroom genuinely dark rather than merely dim
- Tell your household what your sleep window is, and defend it
- Nap before driving home if you feel sleepy
What to avoid
Things that seem reasonable and are not.
- Driving while fighting to stay awake
- Energy drinks across consecutive nights
- Fully flipping your schedule on days off if you return to nights quickly
Where to go next
- Shift Work and Sleep: Common Questions Answered
- Shift Work and Sleep: The Quick Reference
- Shift Work and Sleep — the reference entry
- Napping: What Published Guidance Supports
- The Body Clock: Sorting the Evidence From the Noise
When to speak to a doctor
See a GP if you remain persistently sleepy despite adequate opportunity to sleep, or if you fall asleep involuntarily. In the UK, drivers must inform the DVLA of conditions causing excessive daytime sleepiness. Report safety-critical sleepiness to your employer.
Where this comes from
- Health and Safety Executive — managing shift work
- NHS — Sleep and tiredness
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarised or generalised beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.
Spotted something wrong? Report an error on this page. We correct on the page and say what changed.
